Transposition block



Dec. 22, 1942. DE WlTT R. GODDARD DTRANSPOSITION BLOCK Filed March 30, 1940 INV EN TOR. DE W/TT R. GODDARD ATTORNEY. I

Patented Dec. 22, 1942 UNlTE TRANSPOSITION BLOCK De Witt Rugg Goddard, Riverhead, N. Y., assignor to Radio Corporation of America, a corpora.-

tion of Delaware Application March 30, 1940, Serial No. 327,077

Claims.

This invention relates to a novel type of transposition block which is used to transpose the transmission line from a radio antenna to a re ceiver or transmitter.

An object of this invention is to simplify and improve transposition blocks used on the transmission line of an ultra-high frequency circuit.

Another object of this invention is to provide an improved transmission block made rom two sheets or plates of insulation which is assembled together to form an X section without the use of extra binding members, such as screws, bolts, nuts, etc.

A feature of this invention is provision of a projecting portion on the top and bottom of transposition block to separate he wire. which are secured to block. The transmission blocks known in the prior art generaily consisted of a fiat plate of insulating material which allowed the wires to come rather ciose together at the point where they cross one ano her. This type of block is disadvantageous for reason that snow and sleet will often fill the space between the wires at their cross-over ooint, ther by introducing losses by a change impedance, furthermore, the decrease in spacing of the wires at the cross-over point causes an increase in capacity between the wires, which is undesirable. The type of transmission block of my invention maintains essentially constant spacing between the conductors of the transmission line, thereby decreasing the capacity between the conductors, increasing the voltage rating, and reducing the detrimental effects caused by ice and snow.

This invention will best be understood by referring to the accompanying drawing, in which:

Fig. 1 is a top view of the transposition block of this invention;

Fig. 2 is an end view of Fig. 1;

Fig. 3 is a perspective view showing the transposition block with the two plates separated prior to being assembled.

Referring now in detail to the drawing, the

transposition block of this invention comprises two plates of insulating material I and 2, both in the form of flat plates, assembled to form an X shaped member with a plate portion l and a projecting portion 2' located centrally on both the top and bottom of the plate portion I. The plate portion I of the block is provided with four slots 5, 6, l and 3 through which two conductors 3 and 4 pass so as to be suitably transposed. As will be seen by Fig. 1, slot 5 has a slightly tapered entrance slot 5 which is located parallel to the axis 9. On the opposite side of the plate I, an entrance slot 5 is located and is arranged'diagonally to face a corresponding slot 8". Slot 6 has an entrance slot 6 diagonally located to face a corresponding slot 7'. On the opposite side of the plate are slots ii and I and as shown in Fig. 1, there is also located a slot 8'. It will be noted that slots 5, ii, i and 8 are all located parallel to the axis 9, whereas slots 5", 8", 'i' and 8" are diagonally arrange to face each other. The purpose of entrance slots 5 and ii to 8 and 3" inclusive will be readily seen by referring to Fig. 2, wherein the conductors 3 and 4 are shown in their transposed position. The projecting portion 2' is of such height above and below the plate portion that the conductors are so separated that they are of substantially the same spacing as they pass over the projecting portions as they are when they pass through the slots 5, 6, i and 8. In other words, at a distance. taken from the central axis 9 of block i, the.- outer conductor will be the same from the block axis to the bottom of the slots as it is from thetop and bottom projecting portions 2'. It is preferable that the plate 2' be made of the same insulating material as the rest of the transposition block which is generally that of a good grade of ceramic material.

The manner in which plate I! and the projecting portion 2 is made and assembled will be more completely understood by referring to the detailed showing of Fig. 3. t will be noted that the insulating material forming the plate portion 5 is, slotted on both sides or surfaces, as indicated by slots M and H which are located centrally in the axis 9, and if the plate is to be of. solid material will extend to the central portion. thereof, as indicated by the dot and dash line a. The width of slots H and it is equal to the thickness of the material of plate 2 of the projecting portion 2. Directly opposite slots 5 l and II is an open slot !2 which cuts completely through thesheet of insulating material to the center line 9' and is made slightly smaller in width than that of slots ii and H. On each side of slot l2 and on both surfaces of plate 1 there is provided additional slots l3 and IS, the width of these slots being such that they equal the thickness of the material of plate 2 so that sheet 2 may freely slide therein. The depths of slots l3 and I3 are equal to the depths of slots It and H. The plate comprises a plate of insulating material having an open slot i l which is located on the center of the axis 9 and opposite from the open slot 52 of plate l, and extends to the center line 9. Slots l5 and iii are located below slot I i and extend upward to center line 9'. The width of slots i4, i5 and i5 are equal to that of the narrow open slot l? of plate I. The depths of slots 5:": and iii are made such that they permit plate 2 to slide in the slots l3 and I3 of sheet i. It will be noted that with this construction, the transposition block may be assembled without the use of any tools whatsoever, as the natural springiness in the material will generally suffice to maintain the two parts embodiment of this invention, the of the transposition block is perforated either a single large aperture 95 shown in l, or a system 01" large and small apertures ll so as to further reduce the dielectric ial in the electrostatic field of the wires, thereby still further reducing the capacity between the conductors and the losses in the line.

Although only a few embodiments of this invention are shown, it is to be distinctly understood that it should not be limited precisely thereto.

What claimed is:

l. A transposition block consisting of two fixed plates of insulating material, each one of said plates being partially slotted for engaging the other in a plane at right angles thereto to form a unitary structure, one of said plates having a plurality of slots arranged in adjacent pairs for engaging a pair of conductors, the other plate having a width substantially equal to the distance between the inside ends of adjacent conductor slots on the first plate to space a pair of conductors in constant spacing relationship as they cross one another at the transposition points.

2. A transposition block consisting of two plates of insulating material, each one of said plates being partially slotted for engaging the otin a complementary relationship, said plates being located in planes at right angles to each other, one of said plates having engaging means to retain a pai of conductors of a transmis. line in transposed relationship, the other plate arranged to maintain a constant spacing between said conductors at the transposition points.

3. A transposition block consisting of two plates of insulating material, each one of said plates being slotted for engaging the other to form a unitary structure having an X crosssection, at least one of said plates having engaging r ans to retain a pair of conductors of a transr. -ssion line in transposed relationship, the other plate being arranged to maintain a constant spacing between said conductors at the transposition points.

l. A transposition block consisting of two plates of insulating material, each one of said plates being slotted hali-way through its length for e aging the other to form a unitary structure having an X cross-section, at least one of said plates having engaging means to retain and space a pair of conductors of a transmission line in transposed relationship at the transposition points.

5. A transposition block consisting of two plates, one plate forming a plate portion having a plurality of slots arranged in adjacent pairs for engaging a pair or" conductors, the other plate forming a projecting portion having a projection substantially equal to the distance between the inner ends of the adjacent conductor slots on said plate portion, said projecting portion being centrally located on the top and bottom portions of said block to space said conductors apart as they pass over said plate portion.

6. A transposition block consisting of two plates, one plate forming a plate portion having two slots on each side thereoi and located opposite each other, said slots being arranged for engaging a pair of conductors, the other plate forming a projection portion having a projection substantially equal to the distance between the inner ends of opposite conductor slots on said plate portion, said projecting portion being centrally located on the top and bottom portion of said block to space said conductors apart as they pass over said plate portion.

'7. A transposition block consisting of two plates, one plate forming a plate portion having a plurality of slots arranged in adjacent pairs for engaging a pair of conductors, the other plate forming a projecting portion having a projection substantially equal to the distance between the inner ends of adjacent conductor slots on said plate portion, said projecting portion being centrally located on the top and bottom portions of said block to space said conductors apart as they pass over said plate portion, and a central aperture in said plate portion to reduce the dielectric material at a point where the conductors cross each other.

8. A transposition block consisting of two plates of ceramic material, one plate forming a plate portion having a plurality of slots arranged in adjacent pairs for engaging a pair of conductors, the other plate forming a projecting portion having a projection substantially equal to the distance between the inner ends of adjacent con ductor slots on said plate portion, said projecting portion being centrally located on the top and bottom portion of said block to space said conductors apart as they pass over said plate portion.

9. A transposition block consisting of two plates of insulation material, at least one of said plates having a plurality of apertures therein, each one of said plates being partially slotted for engaging the other in planes at right angles to each other to form a unitary structure, one of said plates having engaging means to space and retain a pair of conductors of a transmission line in transposed relationship, the other plate arranged to maintain a substantially constant spacing between said conductors at the transposition points.

10. A transposition block consisting of two plates of insulation material, each one of said panels being slotted halfway through its length for engaging the other to form unitary structure having an X crossection, and at least one of said plates having eng ging means to retain a pair of conductors, at least one of said plates having apertures therein to reduce the dielectric material in the electrostatic field of the conductors, the other plate having a single aperture and being arranged to maintain a constant spacing between said conductors at the transposition points.

DE WITT RUGG GODDARD. 

